perf: arm_dsu: Support DSU ACPI devices

Add support for probing device from ACPI node.
Each DSU ACPI node and its associated cpus are inside a cluster node.

Signed-off-by: Tuan Phan <tuanphan@os.amperecomputing.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/1600106656-9542-1-git-send-email-tuanphan@os.amperecomputing.com
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/drivers/perf/arm_dsu_pmu.c b/drivers/perf/arm_dsu_pmu.c
index 96ed93c..98e68ed 100644 (file)
--- a/drivers/perf/arm_dsu_pmu.c
+++ b/drivers/perf/arm_dsu_pmu.c
@@ -11,6 +11,7 @@
 #define DRVNAME                PMUNAME "_pmu"
 #define pr_fmt(fmt)    DRVNAME ": " fmt
 
+#include <linux/acpi.h>
 #include <linux/bitmap.h>
 #include <linux/bitops.h>
 #include <linux/bug.h>
@@ -603,18 +604,19 @@ static struct dsu_pmu *dsu_pmu_alloc(struct platform_device *pdev)
 }
 
 /**
- * dsu_pmu_dt_get_cpus: Get the list of CPUs in the cluster.
+ * dsu_pmu_dt_get_cpus: Get the list of CPUs in the cluster
+ * from device tree.
  */
-static int dsu_pmu_dt_get_cpus(struct device_node *dev, cpumask_t *mask)
+static int dsu_pmu_dt_get_cpus(struct device *dev, cpumask_t *mask)
 {
        int i = 0, n, cpu;
        struct device_node *cpu_node;
 
-       n = of_count_phandle_with_args(dev, "cpus", NULL);
+       n = of_count_phandle_with_args(dev->of_node, "cpus", NULL);
        if (n <= 0)
                return -ENODEV;
        for (; i < n; i++) {
-               cpu_node = of_parse_phandle(dev, "cpus", i);
+               cpu_node = of_parse_phandle(dev->of_node, "cpus", i);
                if (!cpu_node)
                        break;
                cpu = of_cpu_node_to_id(cpu_node);
@@ -631,6 +633,36 @@ static int dsu_pmu_dt_get_cpus(struct device_node *dev, cpumask_t *mask)
        return 0;
 }
 
+/**
+ * dsu_pmu_acpi_get_cpus: Get the list of CPUs in the cluster
+ * from ACPI.
+ */
+static int dsu_pmu_acpi_get_cpus(struct device *dev, cpumask_t *mask)
+{
+#ifdef CONFIG_ACPI
+       int cpu;
+
+       /*
+        * A dsu pmu node is inside a cluster parent node along with cpu nodes.
+        * We need to find out all cpus that have the same parent with this pmu.
+        */
+       for_each_possible_cpu(cpu) {
+               struct acpi_device *acpi_dev;
+               struct device *cpu_dev = get_cpu_device(cpu);
+
+               if (!cpu_dev)
+                       continue;
+
+               acpi_dev = ACPI_COMPANION(cpu_dev);
+               if (acpi_dev &&
+                       acpi_dev->parent == ACPI_COMPANION(dev)->parent)
+                       cpumask_set_cpu(cpu, mask);
+       }
+#endif
+
+       return 0;
+}
+
 /*
  * dsu_pmu_probe_pmu: Probe the PMU details on a CPU in the cluster.
  */
@@ -676,6 +708,7 @@ static int dsu_pmu_device_probe(struct platform_device *pdev)
 {
        int irq, rc;
        struct dsu_pmu *dsu_pmu;
+       struct fwnode_handle *fwnode = dev_fwnode(&pdev->dev);
        char *name;
        static atomic_t pmu_idx = ATOMIC_INIT(-1);
 
@@ -683,7 +716,16 @@ static int dsu_pmu_device_probe(struct platform_device *pdev)
        if (IS_ERR(dsu_pmu))
                return PTR_ERR(dsu_pmu);
 
-       rc = dsu_pmu_dt_get_cpus(pdev->dev.of_node, &dsu_pmu->associated_cpus);
+       if (IS_ERR_OR_NULL(fwnode))
+               return -ENOENT;
+
+       if (is_of_node(fwnode))
+               rc = dsu_pmu_dt_get_cpus(&pdev->dev, &dsu_pmu->associated_cpus);
+       else if (is_acpi_device_node(fwnode))
+               rc = dsu_pmu_acpi_get_cpus(&pdev->dev, &dsu_pmu->associated_cpus);
+       else
+               return -ENOENT;
+
        if (rc) {
                dev_warn(&pdev->dev, "Failed to parse the CPUs\n");
                return rc;
@@ -752,11 +794,21 @@ static const struct of_device_id dsu_pmu_of_match[] = {
        { .compatible = "arm,dsu-pmu", },
        {},
 };
+MODULE_DEVICE_TABLE(of, dsu_pmu_of_match);
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id dsu_pmu_acpi_match[] = {
+       { "ARMHD500", 0},
+       {},
+};
+MODULE_DEVICE_TABLE(acpi, dsu_pmu_acpi_match);
+#endif
 
 static struct platform_driver dsu_pmu_driver = {
        .driver = {
                .name   = DRVNAME,
                .of_match_table = of_match_ptr(dsu_pmu_of_match),
+               .acpi_match_table = ACPI_PTR(dsu_pmu_acpi_match),
                .suppress_bind_attrs = true,
        },
        .probe = dsu_pmu_device_probe,
@@ -826,7 +878,6 @@ static void __exit dsu_pmu_exit(void)
 module_init(dsu_pmu_init);
 module_exit(dsu_pmu_exit);
 
-MODULE_DEVICE_TABLE(of, dsu_pmu_of_match);
 MODULE_DESCRIPTION("Perf driver for ARM DynamIQ Shared Unit");
 MODULE_AUTHOR("Suzuki K Poulose <suzuki.poulose@arm.com>");
 MODULE_LICENSE("GPL v2");